One common wireless communication system configuration employs equipment located at a centralized location (for example, at a facility that is controlled by a wireless service provider) and equipment that is located at a location that is remote from the centralized location (for example, at a facility or site that is not controlled by the wireless service provider). The former equipment is also referred to here as a “hub unit” or “host unit” and the latter equipment is also referred to here as a “remote unit.”
One example of such a system is a distributed antenna system (DAS) in which radio frequency (RF) signals are communicated between a host unit and one or more remote antenna units (RAUs). In such a DAS, the host unit is communicatively coupled to one or more base stations (for example, via wired connection or via wireless connection). Downlink RF signals are received from the base station at the host unit. The host unit uses the downlink RF signals to generate a downlink transport signal for transmitting to one or more of the RAUs. Each such RAU receives the downlink transport signal and reconstructs the downlink RF signals from the downlink transport signal and causes the reconstructed downlink RF signals to be radiated from at least one antenna coupled to or included in that RAU. A similar process is performed in the uplink direction. Uplink RF signals received at one or more RAUs are used to generate respective uplink transport signals that are transmitted from the respective RAUs to the host unit. The host unit receives and combines the uplink transport signals transmitted from the RAUs. The host unit reconstructs the uplink RF signals received at the RAUs and communicates the reconstructed uplink RF signals to the base station. In this way, the coverage of the base station can be expanded using the DAS.
In some DAS deployments, the remote antennas are installed on a utility pole or other urban street furniture such as bus shelters, traffic control signals, mail boxes or other structures. In some such deployments, the RAU for each pole-mounted remote antenna must be housed entirely within the utility pole, for example, for zoning reasons or for security reasons. However, it can be difficult to mount an RAU to the interior of such a confined space. Also, it can be difficult to service an RAU that is located within such a confined space.